Carrier 50SZ Series - To Use Cooling Charging Charts; Indoor Airflow and Airflow Adjustments

Accurate pressure gage and temperature sensing devices are
required. Connect the pressure gage to the service port on the
suction line. Mount the temperature sensing device on the suction
line and insulate it so that the outdoor ambient does not affect the
reading. Indoor air CFM must be within the normal operating
range of the unit.
TO USE COOLING CHARGING CHARTS
Take the outdoor ambient temperature and read the suction
pressure gage. Refer to the chart to determine what the suction
temperature should be.
NOTE: If the problem causing the inaccurate readings is a
refrigerant leak, refer to Check for Refrigerant Leaks section.
INDOOR AIRFLOW AND AIRFLOW ADJUSTMENTS
For heating and cooling operation, the recommended airflow
is 350 to 450 cfm for each 12,000 Btuh of rated cooling
capacity. For units with optional electric heat, the airflow
must not be reduced below the levels stated in Table 2.
Failure to maintain these airflows could result in damage to
the unit.
Table 5 shows both heating and cooling airflows at various
external static pressures. Refer to these tables to determine the
airflow for the system being installed.
NOTE: Be sure that all supply-and return-air grilles are open, free
from obstructions, and adjusted properly.
Airflow can be changed by changing the lead connection of the
blower motor.
Fig. 17—Typical Heat Pump Operation, Heating Mode
C00095
COMPRESSOR
ACCUMULATOR
OUTDOOR COIL
INDOOR COIL
LCS
LEGEND
HPS – High Pressure Switch
LCS – Loss of Charge Switch
Accurater
®
Metering Device
Arrow indicates direction of flow
Bypass
Position
Metering
Position
HPS
Fig. 18—Typical Heat Pump Operation, Cooling Mode
C00096
COMPRESSOR
ACCUMULATOR
OUTDOOR COIL
INDOOR COIL
LCS
LEGEND
HPS – High Pressure Switch
LCS – Loss of Charge Switch
Accurater
®
Metering Device
Arrow indicates direction of flow
Metering
Position
Bypass
Position
HPS
13